A court in Egypt has sentenced the prominent human rights activist Sanaa Seif to six months in prison in absentia for "insulting the judiciary".

Seif was summoned by a prosecutor on suspicion of inciting protests in April against President Abdul Fattah al-Sisi.

But she did not comply, which the court deemed an insult.

Seif said she would hand herself in and not contest the verdict because she had no "energy left" and the authorities were determined to jail her.

Security forces launched a renewed crackdown on dissent last month after anti-government protests were triggered by Mr Sisi's controversial decision to hand over control of two islands in the Red Sea to Saudi Arabia.

Hundreds of people, including lawyers, activists and journalists, were reportedly detained in the days leading up to and during the latest demonstrations on 25 April.

A 2013 law, passed months after Mr Sisi led the military's overthrow of President Mohammed Morsi, gives the authorities the right to ban any gathering of more than 10 people in a public place.

Seif was herself sentenced to two years in prison in 2014 after being convicted of taking part in a protest against the law, but was released last September after being pardoned by the president.

She is the daughter of the late human rights lawyer Ahmed Seif al-Islam and the sister of the influential blogger Alaa Abdel Fattah, who has been imprisoned since February 2015, also for violating the protest law.